Increasing demand for more powerful and convenient data and information communication has spawned a number of advancements in communications technologies, particularly in wireless communication technologies. A number of technologies have been developed to provide the convenience of wireless communication in a variety of applications, in various locations. This proliferation of wireless communication has given rise to a number of manufacturing and operational considerations.
There are an increasing number of fixed and portable wireless applications that require, or can benefit from, operation in accordance with a plurality of communications standards or operational protocols. This is commonly referred to as multi-mode operation. Multi-mode capabilities in wireless communication products allow end-users to purchase a single product that may be used in a variety of locations for reasonable length of time—despite any proliferation of or changes in new technologies or standards. Multi-mode capabilities across wireless networks allow providers to offer new, advanced services to a broader range of customers, while fulfilling the needs of their legacy customer base. Thus, wireless base stations and mobile devices need to support portions of emerging standards, as well as revenue producing existing standards for backward compatibility.
Although multi-mode support can be very desirable, it also presents a number of challenges when designing a multimode product—particularly when attempting to address the needs of disparate or competing communications standards or technologies. Commonly, the particular standard or technology associated with each “mode” of a multi-mode device requires substantially unique componentry or circuitry. As such, wireless system designers very rarely—if ever—provide a truly universal, single multi-mode device. Usually, conventional multi-mode systems comprise several devices—each designed to address one particular communications standard or technology—that are packaged together as a single multi-mode product.
Consider, for example, two such technologies which are continuously growing in usage and deployment and, as such, are increasingly targeted for inclusion in multi-mode devices. Wideband Code Division Multiple Access (WCDMA) is a third-generation (3G), wideband, spread-spectrum mobile telecommunication air interface that utilizes code division multiple access multiplexing (CDMA). GSM (Global System for Mobile communications) is currently one of the most popular standards for mobile phones in the world. Although GSM continues to evolve, it is widely regarded as a narrow-band, second generation (2G) technology. Various improvements nonetheless seek to keep GSM viable—such as higher speed data transmission introduced with Enhanced Data rates for GSM Evolution (EDGE) technolgoy.
WCDMA has a much more complex physical layer structure and operation than GSM—due, at least in part, to its much wider signal band. Along with additional complexity come a number of additional specifications and requirements. For example, WCDMA systems commonly utilize a ZIF (zero intermediate frequency) based architecture—due to their wideband operation—whereas GSM systems typically rely upon near-ZIF (NZIF) architectures compatible with their relatively narrow band operations.
In order to design a multi-mode product that conforms to both architecture and operational schemes, conventional devices and systems usually combine many different components and modules, each targeted to support operation and processing in either a ZIF or NZIF protocol. Most such conventional components and modules are designed to function only in one operational context—either the wideband (ZIF) or the narrow band (NZIF)—not in both. As a result, a large number of inefficiencies are introduced to the production and operation of conventional multi-mode devices, which increase device and system costs and introduce a greater potential for system reliability and performance problems.
As a result, there is a need for a system that provides a single receiver or transceiver architecture that efficiently supports both wideband and narrow band operational modes (i.e., ZIF and NZIF)—obviating the need for multiple, specialized components within a single multi-mode device—while providing efficient and dependable wireless communications, in an easy and cost-effective manner.